Acrylic Acid → N,N'-Dicyclohexylurea

Participants

Reaction Steps

The adhesive was converted to a switchable adhesive. The method used for esterification of the carboxylic acid groups pendant to the prepolymer chain employed a dehydrating agent, dicyclohexylcarbodiimide (DCC). This was used in conjunction with a dimethylaminopyridine catalyst with the reaction proceeding at room temperature. The following general procedure was initially used for the esterification reaction. For Example 9a), 6.09 g of base PSA (containing 0.0068 moles acrylic acid) was placed in a dry jar along with 1.41 g of anthracenemethanol (0.0068 moles), 1.39 g DCC (0.0068 moles) and 0.33 g DMAP (0.00027 moles). Approximately 100 ml of anhydrous tetrahydrofuran (THF) was added to the reaction mixture which was left stirring overnight (˜24 hours). A precipitate was formed as a by-product of the esterification (dicyclohexylurea, DHU) which was insoluble in THF and was therefore filtered from the PSA solution. A viscous yellow liquid was produced which was then spread thinly onto Melinex for UV irradiation.

Provenance & Evidence